Safety system for therapeutic lamps



y 1935. R. c. HYDE ET m. 2,002,776

SAFETY SYSTEM FOR THERAFEHJTIC LAMPS Filed Dec. 5, 19315 2 Sheets-Sheet 1 III May 28, 1935.

R. C. HYDE ET AL SAFETY SYSTEM FOR THERAPEUTIC LAMPS Filed Dec. 5, 1953 2 Sheets-Sheet 2 Patented May 28, 1935 UNITED STATES PATENT OFFICE SAFETY SYSTEM FOR THERAPEUTIC LAIHPS Wilmington, Del., a

corporation of Delaware Application December 5, 1933, Serial No. 700,978

4 Claims.

This invention relates to therapeutic lamps and has particular reference to a safety system for employment with therapeutic lamps requir ing high voltage electric circuits for their op- 5 eration.

In connection with electro-therapeutic treatments, it is the common practice to employ a lamp or other device which requires electric current at relatively high voltages for their operation, and it frequently occurs that in making connections for the lamps and in disconnecting the lamps during their ordinary use, the high potential causes relatively long arcs to be formed, exposing the person operating or handling the lamp to dangerous electric shocks.

This is particularly true in the type of therapeutic apparatus commonly employed for producing ultraviolet ray emanations,'such apparatus ordinarily employing a transformer housed in a casing provided with suitable receptacles into which plug connections may be made for the purpose of supplying high tension current to the burners. Such plug connections are commonly employed for the purpose of allowing a rather flexible conductor to be used to conduct current to the burners so that the burners may be moved to various positions for the treatment of different parts of a persons body which are desired to be subjected to ultraviolet ray emanations.

It is, therefore, an object of our invention to provide a system of electric current supply and control for such therapeutic lamps, in which any disconnection of the lamp will automatically stop the supply of current thereto before an arc can be drawn.

Another object of the invention is to provide a control system for therapeutic lamps of the character set forth, in which plug connections are employed to conduct high potential current, and are provided with means for automatically disconnecting the lamp from its source of low voltage supply when said plug connections are operated to disconnect the high voltage conductors.

Another object of the invention is to provide a therapeutic lamp employing a transformer with plug connections for conducting high potential from the secondary winding of the transformer which plug connections, when disconnected, will automatically break the circuit to the primary winding of the transformer.

Other objects and advantages will be apparent from a study of the following specifications read in connection with the accompanying drawings, wherein Figure 1 is a diagrammatic view of a therapeutic lamp embodying plug connections in accordance with our invention;

Fig. 2 is an exploded sectional view of one of the plug and receptacle connections employed in the practice of our invention;

Fig. 3 is a detail View of a portion of the plug connection employed with our invention;

Fig. 4 is a detail plan view of a receptacle employed in the practice of our invention, showing a portion of the cover thereof broken away to expose the interior mechanism thereof;

Fig. 5 is a detail plan view of the rear side of a portion of the receptacle employed in the practice of our invention; and

Fig. 6 is a diagrammatic view illustrating the method of wiring the lamp in accordance with our invention,

Referring to the drawings, we have illustrated in Fig. l a therapeutic lamp employed for the purpose of producing ultraviolet ray emanations, such as is commonly employed by physicians and in hospitals. Such lamps ordinarily comprise a suitable base I to rest upon a floor having a casing or housing 2 supported thereon to contain and house the transformer employed to supply electric current to the lamps. Such devices ordinarily employ what is known as a body burner or ultraviolet ray lamp 3, having considerable area, such lamp ordinarily being mounted in a suitable reflector 4 rigidly secured upon the outer end of a tubular bracket 5 slidably mounted in a tubular support 6 secured to the upper side of the transformer casing 2 as by means of upstanding posts or brackets 1. Such mounting of the body burner permits the burner to be moved longitudinally relative to the transformer housing 2 to properly position the burner over a selected portion of the body of the patient to be treated and also permits rotation of the burner about the axis parallel to the longitudinal axis of the transformer housing for the purpose of directing the rays emanating from the lamp to any desired portion of the patients body to be treated.

In view of the fact that it is necessary to move the lamp relative to the transformer housing in order to properly position it, it is desirable that electric current which is to be supplied to the lamp be submitted thereto through suitable reflectors, such as are illustrated at 8. Such flexible conductors commonly employed are provided upon each of their ends with plug connections 9 and I0, each of which is adapted to be received in and may make contact with receptacle devices ll, oneof which is ordinarily mounted at I2 in the outer end of the tubular bracket 5, while another of which is usually mounted on the transformer housing 2, as indicated at l3, so that new conductors or cables 8 may be readily substituted at any desired time.

Moreover such therapeutic lamps are usually provided with'orificial burners, such as that illustrated at 14, these oriiicial burners including a relatively small tubular lamp l5 of sufficiently small size to permit its introduction into various body cavities and provided with a suitable handle it to which connection may be made through a plug connection I! to a cable l8 which in turn is connected through a plug connection in a suitable receptacle indicated at 2llmounted upon the transformer housing 2. Again it is desirable that the plug connections I! and I9 be arranged to be readily connected and disconnected so that substitute cables may be employed when desired or the plug l9 may be interchangeably inserted in the receptacle l3, as will be hereinafter pointed out.

It will be understood by those skilled in the art that low voltage electric current may be supplied to the transformer within the housing 2 through a suitable flexible connection 2|, while the current which passes through the cables 8 and I8 will lead from the high potential or secondary winding of the transformer and thus will carry high potential current to the body burner 3 and the orificial lamp I4,

While it is common practice to supply such therapeutic equipment with a suitable switch 22 connected in the circuit for the primary winding for the transformer, it frequently occurs that the person using the equipment fails to open the switch 22 before connecting or disconnecting the lamps through the agency of the plugs 9, ill or E9, and in such instances the high potential cur rent will draw a considerable are which may, and frequently does, extend out of the receptacle into which the plugs are inserted and thus touch the persons using the lamps, producing either a considerable electric shock, or a burn, or both.

One of the types of plug connections employed for interconnecting the lamps with the transformer housing, includes a plug section 23 having a pair of metallic terminals 24 and 25 extending therefrom receivable through openings 26 and 2'l respectively in a cover plate 28 of a receptacle section 29. The receptacle section 29 is provided with suitable metallic terminals 30 and 3i which are offset from direct alignment with the openings 26 and 21 respectively so that it is necessary to partially rotate the plug section 23 relative to the receptacle section 29 after the terminals 24 and 25 have been inserted therein to bring the terminals 24 and 25 into contact engagement with the terminals 30 and 3|. Such action is employed for the purpose of locking the plug section from accidental displacement with respect to the receptacle section 29 by providing suitable enlargements 32 and 33 on the terminals 24 and 25 to engage beneath reduced portions of the openings 26 and 21 when the terminals have been rotated into contact with each other. Thus it is necessary to first insert the terminals 24 and 25 into the receptacle and then to partially rotate the same relative to the receptacle section 29 in order to make connection with the terminals 30 and 3!, and it is necessary to partially rotate the plug section and receptacle section in order to disconnect the two sections the plug is moved relative to to permit the plug to be removed from the receptacle.

We propose to employ this partial rotation of the plug and receptacle sections relative'to each other for the purpose of automatically connecting and disconnecting the primary winding of the transformer to and from its source of supply, thereby insuring that whenever the plug section is removed from the receptacle section no current will flow in the primary winding of the transformer and also insuring that except when the terminals Hand 25 are in actual contact engagement with the terminals 30 and 3! no current will flow through the primary winding of the transformer.

By referring particularly to Figs. 2, 4 and 5, it will be observed that the plug section 23 is provided with a central guiding stem 34 which is adapted to be received through an opening 35 in the top plate 28 of the receptacle section 29, such guiding stem 34 extending entirely through the receptacle section 29 so that the outer end 36 of the stem protrudes through the rear plate 3? of the receptacle 29. Thus by mounting a suitable switching device upon the rear plate 37 of the receptacle the stem 34 may be employed for the purpose of connecting and disconnecting the primary winding of the transformer whenever the receptacle sec tion.

We prefer to form the outermost end 36 of the stem 34 with a flattened section 38 so that by mounting one of the contacts 39, constituting the primary circuit switch with its rear surface substantially in alignment with the axis of the opening 40 in the rear plate 31, the end 33 of the stem may be readily inserted through the opening 40 so that a portion thereof overlies the contact 39 and thus when the plug section 23 is partially rotated to bring the terminals 24 and 25 into contact with the terminals 30 and 3i, the edges 4| of the extending end 36 will engage and move the contact 39 toward its associated contact 92 and thus engage the contacts 39 and 42 to complete the primary circuit for the transformer. Likewise when the plug section is rotated in the reverse direction to permit withdrawal of the terminals 24 and 25 from the receptacle section 29, the flattened portion 38 of the stem will permit the contact 39 to move away from the contact 42 and thus upon the primary circuit.

If desired, a suitable section of insulating material 43 may be mounted upon the contact 39 to prevent current from the low voltage source to pass to the stem 34.

In Fig. 6 we have illustrated diagrammatically one system of wiring which may be employed in the practice of our invention as including a suitable source of low voltage electric current, indicated by the legend 110 v. from one terminal of which a conductor 44 extends directly to one terminal 45 of the primary winding 46 of the transformer 41. The transformer 41 is illustrated as having its primary winding 46 provided with a plurality of taps each of which is connected by a suitable conductor 48, 49 and 50 to respective terminals 5|, 52, and 53 of the switch 22. The movable contact 54 of the switch 22 is illustrated as being connected through a suitable conductor 55 to the movable contacts 39 of each of the primary winding switches associated with the receptacles l3 and 20, while the stationarycontacts 42 are illustrated as being connected through a suitable conductor 56 to the opposite terminal of the source of low voltage supply.

Since it is the usual practice to employ only one of the lamps or burners at any one time, it appears to be satisfactory to connect the switches 39-42 for the receptacles I3 and in parallel relation with each other.

The secondary winding 51 of the transformer is illustrated as being connected directly to the high tension terminals 30 and 3| of the receptacles l3 and 20 as by connecting opposite ends 58 and 59 of the secondary winding to the two terminals 30 of the receptacles, which terminals are also preferably grounded to the metal parts of the apparatus, as indicated at 6|. It will, therefore, be observed that when the plug section 23 for either of the burners 3 and i4 is inserted in either of the receptacles I3 or 20, as by passing the enlargements 32 and 33 in the terminals 24 and 25 through the enlargements 62 on the openings 26 and 21 and then partially rotating the front section 23 to bring the terminals 24 and 25 into actual electrical engagement with the terminals 30 and 3|, the latter rotation will close the circuit to the primary winding of the transformer, while the reverse action thereof will automatically and instantly open the circuit to the primary winding of the transformer. With this arrangement it is impossible for the person employing the therapeutic apparatus to draw an arc between the high potential terminals, since as soon as the contact is broken between the high potential terminals 24 and 30 and 25-3l, no current is flowing through the primary winding of the transformer.

While we have shown and described the preferred embodiment of our invention, we do not wish to be limited to any of the details of construction shown or described herein, except as defined in the appended claims.

We claim:

1. In a system of the character described, a transformer, a receptacle having a terminal connected to the high potential winding of said transformer, a switch on said receptacle connected in series relation with the primary winding of said transformer, a plug connection connected to said electrical apparatus, and means operably responsive to the insertion of said plug into electrical contact with the terminal in said receptacle for actuating said switch to close the circuit to said primary winding of said transformer.

2. In a system of the character described, a transformer, a receptacle having electrical terminals connected to the high potential winding of said transformer, a switch on said receptacle connected to the low potential winding of said transformer, a plug connection having electrical terminals thereon connected to said electrical apparatus for insertion in and engagement with said receptacle terminals, and means operably responsive to the insertion of said plug terminals into contacting engagement with said receptacle terminals for closing said switch, and responsive to the movement of said plug terminals out of engagement with said receptacle terminals for opening said switch.

3. In a system of the character described, a transformer, a receptacle having electrical terminals connected to the high potential winding of said transformer, a switch on said receptacle connected to the low potential winding of said transformer, a plug connection having electrical terminals thereon connected to said electrical apparatus for insertion in and engagement with said receptacle terminals, a cover plate on said receptacle having openings therein through which said plug terminals may pass, 'means mounting said receptacle terminals out of alignment with the openings in said plate whereby said plug terminals must be inserted through said openings and then rotated relative to said receptacle to engage said receptacle terminals, a guide stem on said plug in fixed relation thereto, and means on said guide stem operably responsive to rotation thereof for engaging and closing said switch only when said plug terminals are in engagement with said receptacle terminals.

4. In a system of the character described, a transformer having a primary winding and a secondary winding, receptacle means having terminals connected to the secondary winding of said transformer, a plug having terminals connected to said electrical apparatus for engagement with said receptacle, terminals and means connected to the primary winding of said transformer and operable responsive to disengagement of said plug'and receptacle terminals for opening the circuit to said primary winding.

RALPH C. HYDE. ELLIS O. ERICKSON. 

